Which of the following calculations require the use of the addition rule of probability?
A) Calculate the probability of black offspring from the cross AaBb × AaBb, where B is the symbol for black.
B) Calculate the probability of children with both cystic fibrosis and polydactyly when parents are each heterozygous for both genes.
C) Calculate the probability of each of four children having cystic fibrosis if the parents are both heterozygous.
D) Calculate the probability of a child having either sickle-cell anaemia or cystic fibrosis if parents are each heterozygous for both.

Question

Quizplus · Accepted Answer

The addition rule of probability is used when calculating the probability of two or more mutually exclusive events occurring. In option D, the events of sickle-cell anaemia and cystic fibrosis are mutually exclusive. Therefore, the addition rule of probability is required to calculate the probability of either one occurring. In options A, B, and C, the multiplication rule of probability is used to calculate the probabilities of independent events occurring.

Which of the Following Calculations Require the Use of the Addition